C :

#include"stdio.h"
int main(){
	double in,out;
	scanf("%lf",&in);
    out=(5.0/9)*(in-32);
    printf("%.2f",out);
    return 0;
}

C++ :

#include<iostream>
using namespace std;

int main() {
	float c, f;
	cin >> f;
	printf("%.2f",5.0 / 9 * (f - 32));
	return 0;
}